Does liquid CO2 replace pressurized CO2 gas?

While liquid carbon is often marketed as a source of carbon, most planted tank experts agree that it is a poor replacement for CO₂ gas. In reality, many aquatic plants prefer to grow with their leaves out of water because it is easier and faster to directly access CO₂ from the air. Therefore, people set up high tech tanks to help their underwater plants by injecting more CO₂ gas into the water at concentrations ranging from 10-30 ppm. Some initial studies have analyzed how much is CO₂ released from recommended doses of liquid carbon, and the numbers were significantly lower than pressurized CO₂. In fact, a normal aquarium with good surface agitation and gas exchange using an air stone or filter results in approximately 3-5 ppm CO₂ in the water, which is still higher than what liquid carbon appears to supply.

For more information on liquid carbon and its uses, read our full article here.